In general, robot cleaners can be classified into a cord type and a cordless type.
There has been proposed the wire type cleaner which has a cable assembly disclosed in Japanese Patent Laid-open Publication No. Sho 62-152422.
The core type cleaner disclosed in this Japanese Patent, however, a moving range of the cleaner is restricted by the length of a power cord for connecting the cleaner with a power source terminal.
Also, when the cleaner cleans several rooms, a plug of the power cord must be frequently plugged in the power source terminal at different positions because the power cord is short.
As another conventional cleaner, there is, of course, the well known cordless type cleaner disclosed in Japanese Patent laid-open pyung 3-184105.
Although the cordless type cleaner disclosed in this Japanese Patent laid-open publication, a moving range not restricted by the length of the power cord, nevertherless, not only can the cleaning not be performed for a long time but also a battery may have to be charged at any time because a battery capacity is restricted.
In order to overcome the problems described above, if the battery were manufactured to be of increased capacity, not only a battery weight as well as cost of the cleaner is increased, but also it is very inconvenient to use the battery. Further, the cordless type cleaner operates without the power cable only in the case of an automatic mode.